The present invention relates to a hybrid drive apparatus.
As disclosed in Japanese Patent Application Publication No. JP-A-2005-61498, there exists a hybrid drive apparatus that is structured such that a first motor, a power distributing planetary gear, a second motor, and a transmission are provided in a drive transmission system from a side of an input shaft disposed on an engine side to an output shaft side.
In this hybrid drive apparatus, excessive or deficient torque on the output side can be compensated for by the second motor while maintaining the rotation speed of the engine in a state of high fuel efficiency through the actions of the first motor.
Japanese Patent Application Publication No. JP-A-2005-61498 proposes a hybrid drive apparatus in which a transmission, including three shift speeds, is interposed between a second rotary shaft, which rotates integrally with the second motor, and a drive shaft for outputting power, whereby shifting can be performed without reducing the power transfer efficiency.
Japanese Patent Application Publication No. JP-A-2005-206136 provides a switch clutch and a switch brake as a differential state switching apparatus for selectively switching a power distribution mechanism between an operational state (continuously variable shifting state) in which the power distribution mechanism can operate as an electric continuously variable transmission, and a constant shifting state in which the power distribution mechanism can operate as a transmission having a constant speed ratio. As a result, a hybrid drive apparatus having a reduced size and improved fuel efficiency is obtained. In Japanese Patent Application Publication No. JP-A-2005-206136, a transmission that is capable of realizing between four and eight forward speeds and one or two reverse speeds is employed.